libtls: const workarounds for X509_NAME in OCSP for OpenSSL 4

The API to look up a cert by subject or issuer name clearly only needs to
do name comparisons in a collection of certs so should by all means take a
const X509_NAME * as an argument. However, this isn't all that easy to do
and hence it's only in OpenSSL 4 that this obvious step was reached.

This means that there is no way around casting for older code. One could
cast the return value of X509_get_issuer_name() or the argument passed to
the two lookups by subject. jsing slightly prefers the second approach,
so this is what we do here.

ok djm jsing kenjiro

1 files changed, 5 insertions, 4 deletions

diff --git a/src/lib/libtls/tls_ocsp.c b/src/lib/libtls/tls_ocsp.c
index bfd06e3c6a..c65911920a 100644
--- a/src/lib/libtls/tls_ocsp.c
+++ b/src/lib/libtls/tls_ocsp.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: tls_ocsp.c,v 1.26 2024/03/26 06:24:52 joshua Exp $ */
+/*      $OpenBSD: tls_ocsp.c,v 1.27 2026/03/28 11:49:31 tb Exp $ */
 /*
  * Copyright (c) 2015 Marko Kreen <markokr@gmail.com>
  * Copyright (c) 2016 Bob Beck <beck@openbsd.org>
@@ -130,7 +130,7 @@ static OCSP_CERTID *
 tls_ocsp_get_certid(X509 *main_cert, STACK_OF(X509) *extra_certs,
     SSL_CTX *ssl_ctx)
 {
-        X509_NAME *issuer_name;
+        const X509_NAME *issuer_name;
         X509 *issuer;
         X509_STORE_CTX *storectx = NULL;
         X509_OBJECT *obj = NULL;
@@ -141,7 +141,8 @@ tls_ocsp_get_certid(X509 *main_cert, STACK_OF(X509) *extra_certs,
                 goto out;
 
         if (extra_certs != NULL) {
-                issuer = X509_find_by_subject(extra_certs, issuer_name);
+                issuer = X509_find_by_subject(extra_certs,
+                    (X509_NAME *)issuer_name);
                 if (issuer != NULL) {
                         cid = OCSP_cert_to_id(NULL, main_cert, issuer);
                         goto out;
@@ -155,7 +156,7 @@ tls_ocsp_get_certid(X509 *main_cert, STACK_OF(X509) *extra_certs,
         if (X509_STORE_CTX_init(storectx, store, main_cert, extra_certs) != 1)
                 goto out;
         if ((obj = X509_STORE_CTX_get_obj_by_subject(storectx, X509_LU_X509,
-            issuer_name)) == NULL)
+            (X509_NAME *)issuer_name)) == NULL)
                 goto out;
 
         cid = OCSP_cert_to_id(NULL, main_cert, X509_OBJECT_get0_X509(obj));